1. Technical Field
This disclosure relates to an image forming apparatus and more specifically to an image forming apparatus including a recording head to eject liquid droplets.
2. Description of the Related Art
Image forming apparatuses are used as printers, facsimile machines, copiers, plotters, or multifunction devices having two or more of the foregoing capabilities. As one type of image forming apparatuses employing a liquid-ejection recording method, for example, inkjet recording apparatuses are known that use a recording head (liquid ejection head or liquid-droplet ejection head) for ejecting droplets of liquid (e.g., ink).
Such an image forming apparatus employing a liquid-ejection recording method may have a maintenance device (maintenance and recovery device) to maintain the stability of ejection performance of nozzles of a recording head. The maintenance device includes a cap and a wiping member. The cap caps a nozzle face of the recording head to prevent drying of ink in nozzles and intrusion of dust into nozzles. The wiping member (also referred to as, e.g., a wiper blade, wiping blade, or blade) wipes the nozzle face of the recording head for cleaning. For example, after discharging ink having an increased viscosity due to drying into the cap, such an image forming apparatus performs a recovery operation to wipe the nozzle face with the wiping member and form menisci in nozzles.
For such an image forming apparatus, for example, a droplet ejection face (nozzle face) of a recording head for ejecting liquid droplets may be oriented obliquely downward so that the image forming apparatus be usable regardless of whether an apparatus body is vertically or horizontally arranged (e.g., JP-2006-142625-A).
Such an image forming apparatus is designed to prevent liquid (waste liquid) discharged from the recording head into the cap from leaking from the cap in any of the vertical or horizontal arrangement.
For example, for an image forming apparatus described in JP-2006-142625-A, the cap has a bottom face being upright or tilted relative to the vertical direction in any of the vertical or horizontal arrangement. In other words, the image forming apparatus has a cap bottom face forming the bottom face of the cap in one of the vertical or horizontal arrangement, a cap side wall forming a recessed portion between the cap side wall and the cap bottom face, and a waste-liquid receptacle to store waste liquid in the recessed portion and having a blocking member disposed upright from the cap side wall toward the recessed portion to prevent waste liquid on the bottom face of the cap from leaking to the outside of the cap via the side wall of the cap.
However, for the image forming apparatus, in a configuration in which the cap is tilted relative to the vertical direction, the amount of waste liquid discharged into the cap is controlled to be smaller than in a configuration in which an opening of the cap is horizontally arranged, to prevent waste liquid from flowing over the blocking member. For such a configuration, the inventors have recognized that, if the discharged amount of waste liquid is too large, the waste liquid may flow over the blocking member to the outside.
In addition, in the vertical arrangement of the apparatus body, waste liquid may be blocked by the blocking member at a position lower than a suction port of the cap or retained by capillary action of the recessed portion, thus preventing waste liquid from being discharged from the cap.
However, the inventors have recognized that, if waste liquid remains in the cap, solid components in ink may accumulate near the blocking member or in the recessed portion, thus causing leakage of ink over time. In addition, such ink remaining in the cap may absorb moisture from nozzles to compensate moisture loss due to drying, thus causing a reduced reliability in ejection performance after capping operation.